From 13ab902ec7c398026f5574afb7dc91f97749abae Mon Sep 17 00:00:00 2001
From: Valentin Gosu <valentin.gosu@gmail.com>
Date: Thu, 16 Sep 2021 08:31:03 +0000
Subject: [PATCH] Bug 1730494 - Show error in webconsole when resource is
 blocked by CORP headers r=necko-reviewers,dragana

Differential Revision: https://phabricator.services.mozilla.com/D125392
---
 netwerk/locales/en-US/necko.properties     |  2 ++
 netwerk/protocol/http/HttpChannelChild.cpp | 24 ++++++++++++++++++++++
 netwerk/protocol/http/HttpChannelChild.h   |  2 ++
 3 files changed, 28 insertions(+)

diff --git a/netwerk/locales/en-US/necko.properties b/netwerk/locales/en-US/necko.properties
index f630d979f714..fea6c3189e0a 100644
--- a/netwerk/locales/en-US/necko.properties
+++ b/netwerk/locales/en-US/necko.properties
@@ -30,6 +30,8 @@ AutomaticAuth=You are about to log in to the site “%1$S” with the username 
 
 TrackerUriBlocked=The resource at “%1$S” was blocked because content blocking is enabled.
 UnsafeUriBlocked=The resource at “%1$S” was blocked by Safe Browsing.
+# LOCALIZATION NOTE (CORPBlocked): %1$S is the URL of the blocked resource. %2$S is the URL of the MDN page about CORP.
+CORPBlocked=The resource at “%1$S” was blocked due to its Cross-Origin-Resource-Policy header (or lack thereof). See %2$S
 CookieBlockedByPermission=Request to access cookies or storage on “%1$S” was blocked because of custom cookie permission.
 CookieBlockedTracker=Request to access cookie or storage on “%1$S” was blocked because it came from a tracker and content blocking is enabled.
 CookieBlockedAll=Request to access cookie or storage on “%1$S” was blocked because we are blocking all storage access requests.
diff --git a/netwerk/protocol/http/HttpChannelChild.cpp b/netwerk/protocol/http/HttpChannelChild.cpp
index ca3f63dec60d..0dfa84eccad2 100644
--- a/netwerk/protocol/http/HttpChannelChild.cpp
+++ b/netwerk/protocol/http/HttpChannelChild.cpp
@@ -1010,6 +1010,8 @@ void HttpChannelChild::DoOnStopRequest(nsIRequest* aRequest,
   };
   checkForBlockedContent();
 
+  MaybeLogCOEPError(aChannelStatus);
+
   // See bug 1587686. If the redirect setup is not completed, the post-redirect
   // channel will be not opened and mListener will be null.
   MOZ_ASSERT(mListener || !LoadWasOpened());
@@ -2976,6 +2978,28 @@ HttpChannelChild::LogMimeTypeMismatch(const nsACString& aMessageName,
   return NS_OK;
 }
 
+nsresult HttpChannelChild::MaybeLogCOEPError(nsresult aStatus) {
+  if (aStatus == NS_ERROR_DOM_CORP_FAILED) {
+    RefPtr<Document> doc;
+    mLoadInfo->GetLoadingDocument(getter_AddRefs(doc));
+
+    nsAutoCString url;
+    mURI->GetSpec(url);
+
+    AutoTArray<nsString, 2> params;
+    params.AppendElement(NS_ConvertUTF8toUTF16(url));
+    // The MDN URL intentionally ends with a # so the webconsole linkification
+    // doesn't ignore the final ) of the URL
+    params.AppendElement(
+        u"https://developer.mozilla.org/docs/Web/HTTP/Cross-Origin_Resource_Policy_(CORP)#"_ns);
+    nsContentUtils::ReportToConsole(nsIScriptError::errorFlag, "COEP"_ns, doc,
+                                    nsContentUtils::eNECKO_PROPERTIES,
+                                    "CORPBlocked", params);
+  }
+
+  return NS_OK;
+}
+
 nsresult HttpChannelChild::CrossProcessRedirectFinished(nsresult aStatus) {
   if (!CanSend()) {
     return NS_BINDING_FAILED;
diff --git a/netwerk/protocol/http/HttpChannelChild.h b/netwerk/protocol/http/HttpChannelChild.h
index 0e6681f39844..9a7708d0bb06 100644
--- a/netwerk/protocol/http/HttpChannelChild.h
+++ b/netwerk/protocol/http/HttpChannelChild.h
@@ -257,6 +257,8 @@ class HttpChannelChild final : public PHttpChannelChild,
   // ensure Cacnel is processed before any other channel events.
   void CancelOnMainThread(nsresult aRv);
 
+  nsresult MaybeLogCOEPError(nsresult aStatus);
+
  private:
   // this section is for main-thread-only object
   // all the references need to be proxy released on main thread.